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    <script>
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        const obj = {};
        mp1.set(obj, 6456);
        mp1.set("a", "abc");
        mp1.set(obj, 111);
        
        console.log(mp1)
        console.log("总数：", mp1.size);
        console.log("get('a')", mp1.get("a"));
        console.log("has('a')", mp1.has("a"));
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